Something to discuss...

[missilemaster]

Here is why I like the inner tube method!

[DC]

That's not glued! That grew like that-right?

[mikekeswick]

Air hose is the way to go really.....
Pearl - One clamp every two inches max spacing. Make up a pressure strip with good thick chunks of wood, I make mine 2 x 2 x 3/4, then lay these blocks side by side butting up against each other on a piece of strong material. Glue them in place. You now have a flexible pressure strip.
If you are going to use inner tube with a thin backing then you must use another waste strip/lam as a pressure strip. I make these about 1/4 thick. Still thin enough to follow whatever curve but thick enough to give even pressure across the whole backing.
If you use innertubes and thin backings lams with no pressure strip you run the risk of an inadvertantly crowned backing....don't ask how I know this!

[Buckeye Guy]

Well looks like you learned a lesson there
I use a form on both sides of my limb glue ups  but others don't so it may not be necessary but I dont have those issues  even in a cold shop with thick glue I can get a even press
Never done learning
Have fun
 As for Osage I wish we could get to Illinois , there is have a fellow there that has a barn full of Osage flooring boards that are about 100 years old I would love to sort thru !

[blackhawk]

If you are going to use inner tube with a thin backing then you must use another waste strip/lam as a pressure strip. I make these about 1/4 thick. Still thin enough to follow whatever curve but thick enough to give even pressure across the whole backing.
If you use innertubes and thin backings lams with no pressure strip you run the risk of an inadvertantly crowned backing....don't ask how I know this!

An easy way to combat that is to just leave the belly lam full width,n make your backing strip near final dimension front profile wise...this will avoid the backing strip wanting to cup...if your backing strip is the same width or wider than the belly lam you'll run into that issue almost every time..once cured cut out to near the backing strip on the saw...easy peasy. No pressure strips needed for inner tubes.

[IdahoMatt]

That's some good pudding to put your proof in.  Great job on the glue lines.  Tis a thing of beauty.

[PEARL DRUMS]

Thanks for all the tips guys. Ill do some fixture work this weekend and take another stab. Ive made a good share of glue bows this same way, this one got me and it was only one limb in length!

[Stringman]

I'm learning from this and might have to try another stab at a glue up. Good luck Chris.

[mikekeswick]

If you are going to use inner tube with a thin backing then you must use another waste strip/lam as a pressure strip. I make these about 1/4 thick. Still thin enough to follow whatever curve but thick enough to give even pressure across the whole backing.
If you use innertubes and thin backings lams with no pressure strip you run the risk of an inadvertantly crowned backing....don't ask how I know this!

An easy way to combat that is to just leave the belly lam full width,n make your backing strip near final dimension front profile wise...this will avoid the backing strip wanting to cup...if your backing strip is the same width or wider than the belly lam you'll run into that issue almost every time..once cured cut out to near the backing strip on the saw...easy peasy. No pressure strips needed for inner tubes.

What if you want to use a thin belly lam? 
I use 3mm steel from a steel fabricators. They cut me a slice on their big guillotine whatever width I want for about £2. Thin belly lams allow you to make any shape you want  without having to mess about with steam or heat. Once you get good at doing these sort of things you can work out the required taper and have a basically tillered bow once you've cut the width profile. If i'm making a bow like this I try to make full use of the advantages of the technique.
Once the backing gets to 1/4 inch thick you don't need anything.

[PatM]

BH is talking about width of that lam, not the thickness specifically.

[missilemaster]

If you are going to use inner tube with a thin backing then you must use another waste strip/lam as a pressure strip. I make these about 1/4 thick. Still thin enough to follow whatever curve but thick enough to give even pressure across the whole backing.
If you use innertubes and thin backings lams with no pressure strip you run the risk of an inadvertantly crowned backing....don't ask how I know this!

An easy way to combat that is to just leave the belly lam full width,n make your backing strip near final dimension front profile wise...this will avoid the backing strip wanting to cup...if your backing strip is the same width or wider than the belly lam you'll run into that issue almost every time..once cured cut out to near the backing strip on the saw...easy peasy. No pressure strips needed for inner tubes.

What if you want to use a thin belly lam? 
I use 3mm steel from a steel fabricators. They cut me a slice on their big guillotine whatever width I want for about £2. Thin belly lams allow you to make any shape you want  without having to mess about with steam or heat. Once you get good at doing these sort of things you can work out the required taper and have a basically tillered bow once you've cut the width profile. If i'm making a bow like this I try to make full use of the advantages of the technique.
Once the backing gets to 1/4 inch thick you don't need anything.

 Mike, How many lams are you talking with a thin belly? 4,5?  I can definately see the merits of using thiner stock but at what point does the bow become more glue than wood?

[Arrowind]

Cool thread.  Pearl Drums,  I'm sure you will master this just like everything else you've done.  I like seeing all the comments.  Thanks for sharing.  For what it's worth I've used plastic wrap and inner tubes with good success.  I usually try to make sure the backing has very minimal overlap before glue up as others have said.  Seems to help.  I've also used a combination of tubes and clamps to keep the middle down. Wrap with tubes then add clamps...maybe overkill but I hate having to redo stuff.  Anyway.  Can't wait to see the results.

[mikekeswick]

Missilemaster - You can use a thin bellylam with 3 lams total. Whatever you want. Gluelines can be made to work too! Althought it is heavy stuff it's awfully thin in a finished bow 
PatM - I understand what BH is saying and I agree. There are many ways to skin a cat.....I'm just sharing my way of doing things. You have less chance of lams sliding sideways if they are all the same width as you can clamp them straight, add tape to hold then apply pressure however you see fit. This will also give you more wiggle room when it comes to layout or allows you to use less wood once you are confident in your widths..